Cannot navigate in local HTML numpy documentation.

When I open local numpy documentation in a browser, located at file:///usr/share/doc/python-numpy-doc/html/index.html , search for any function, for example "log" and click it, it goes to an incorrect URL containing the word "undefined". If I modify the URL replacing "undefined" by ".html", it usually works fine, although not always. While this may be a workaround, it is usually very uncomfortable, losing all value of locally installed documentation.

I have the documentation installed by the python-numpy-doc package via apt in Ubuntu 21.04.

Please tell me if this is the right place for this bug, and if I can help.